The present invention relates to pharmaceutical compositions useful in the treatment of heart transplant rejection in mammals which comprise a pharmaceutically acceptable excipient, a therapeutically effective amount of a non-peptide CCR1 receptor antagonist and a sub-nephrotoxic amount of cyclosporin A. The present invention also relates to a method of using such pharmaceutical compositions in treating heart transplant rejection in mammals.
An important component of the inflammatory process involves the migration and activation of select populations of leukocytes from the circulation and their accumulation in the affected tissue. While the idea of leukocyte trafficking is not new, it has enjoyed a renaissance recently following the discovery and characterization of the selectin and integrin families of adhesion molecules and the large family of selective chemotatic cytokines known as chemokines. Chemokine receptors are expressed on leukocytes and process the signals following the binding of the chemokine whereby such signals are eventually transduced into migration or activation of the leukocytes towards the source of the chemokine. Therefore, by regulating the migration and activation of leukocytes from the peripheral blood to extravascular sites in organs, skin, articulations or connective, tissue, chemokines play a critical role in the maintenance of host defense as well as in the development of the immune response.
Originally, the chemokine family of molecules was divided into two groups: the xe2x80x9cCxe2x80x94Xxe2x80x94xe2x80x9d subfamily and the xe2x80x9cCxe2x80x94Cxe2x80x9d subfamily. The characteristic feature of both of these subfamilies is the presence of four cysteine residues in highly conserved positions in the molecules. In the xe2x80x9cCxe2x80x94Cxe2x80x9d chemokine subfamily, the first two residues are adjacent to each other, while in the xe2x80x9cCxe2x80x94Xxe2x80x94Cxe2x80x9d subfamily, a single amino acid residue separates the cysteine residues. A recent description of a xe2x80x9cxe2x80x94Cxe2x80x94xe2x80x9d chemokine appears to represent a new family of chemokines in that the xe2x80x9cxe2x80x94Cxe2x80x9d chemokine lacks two of the four cysteine residues present in the xe2x80x9cCxe2x80x94Cxe2x80x9d subfamily or the xe2x80x9cCxe2x80x94Xxe2x80x94Cxe2x80x9d subfamily.
One member of the xe2x80x9cCxe2x80x94Cxe2x80x9d subfamily of chemokines is macrophage inflammatory protein-1xcex1 (xe2x80x9cMIP-1xcex1xe2x80x9d). It is expressed by cells such as macrophages, T and B lymphocytes, neutrophils and fibroblasts. A recent study (see Karpus, W. J. et al., J. Immunol. (1995), Vol. 155, pp. 5003-5010) provides strong in vivo concept validation for a role of MIP-1xcex1 in a mouse experimental autoimmune encephalomyelitis (xe2x80x9cEAExe2x80x9d) model of multiple sclerosis. Multiple sclerosis is an autoimmune disease mediated by T and B lymphocytes and macrophages, resulting in extensive inflammation and demyelination of white matter in the central nervous system. The study showed that antibodies to MIP-1xcex1 prevented the development of both initial and relapsing disease as well as preventing the infiltration of mononuclear cells into the central nervous system. Treatment with the antibodies was also able to ameliorate the severity of ongoing clinical disease. These results led the investigators to conclude that MIP-1xcex1 plays an important role in the etiology of multiple sclerosis. Another study (see Godiska, R. et al., J. Neuroimmunol. (1995), Vol. 58, pp. 167-176) demonstrated the upregulation of mRNA for a number of chemokines, including MIP-1xcex1, in the lesions and spinal cord of SJL mice (a strain of mice susceptible to Th1 diseases such as EAE) during the course of acute EAE.
RANTES is another member of the Cxe2x80x94C chemokine subfamily (the name RANTES is an acronym derived from some of the original observed and predicted characteristics of the protein and its gene: Regulated upon Activation Normal T cell Expressed presumed Secreted). A wide variety of tissues have been found to express RANTES in a similar pattern to MIP-1xcex1. There is evidence from a number of studies to implicate the abnormal production of RANTES in the progression of rheumatoid arthritis (see Rathanaswami, P. et al., J. Biol. Chem. (1993), Vol. 268, pp. 5834-5839 and Snowden, N. et al., Lancet (1994), Vol. 343, pp. 547-548). Rheumatoid arthritis is a chronic inflammatory disease characterized in part by a memory T lymphocyte and monocyte infiltration, which is believed to be mediated by chemotactic factors released by inflamed tissues. There is strong evidence from other studies implicating RANTES in the pathophysiology of rheumatoid arthritis (see Barnes, D. A. et al, J. Clin. Invest (1998), Vol. 101, pp. 2910-2919 and Plater-Zyberk, C. A. et al., Immunol. Lett. (1997), Vol. 57, pp. 117-120). For example, in a rat adjuvant-induced arthritis (xe2x80x9cAIAxe2x80x9d) model, antibodies to RANTES greatly reduced the development of disease.
These studies and others provide strong evidence that MIP-1xcex1 levels are increased in EAE models of multiple sclerosis and that RANTES levels are increased in rheumatoid arthritis (see, e.g., Glabinski, A. R. et al, Am. J. Pathol. (1997), Vol. 150, pp. 617-630; Glabinski, A. R. et al., Methods Enzymol. (1997), Vol. 288, pp. 182-190; and Miyagishi, R. S. et al., J. Neuroimmunol. (1997), Vol. 77, pp. 17-26). In addition, as described above, these chemokines are chemoattractants for T cells and monocytes, which are the major cell types that are involved in the pathophysiology of these diseases. Therefore, any molecule that inhibits the activity of either of these chemokines would be beneficial in treating these diseases and would therefore be useful as an anti-inflammatory agent.
There also exists strong evidence linking RANTES to organ transplant rejection. The infiltration of mononuclear cells into the interstitium of organ transplants is the hallmark of acute cellular rejection. This cellular infiltrate primarily consists of T cells, macrophages and eosinophils. In a study of RANTES expression during acute renal allograft rejection, RANTES mRNA expression was found in infiltrating mononuclear cells and renal tubular epithelial cells and RANTES itself was found to be bound to the endothelial surface of the microvasculature within the rejecting graft (see Pattison, J. et al., Lancet (1994), Vol. 343, pp. 209-211 and Wiedermann, C. J. et al., Curr. Biol (1993), Vol. 3, pp. 735-739). A recent study (see Pattison, J. M. et al, J. Heart Lung Transplant. (1996), Vol. 15, pp. 1194-1199) suggests that RANTES may play a role in graft atherosclerosis. Increased levels of RANTES, both mRNA and protein, were detected in mononuclear cells, myofibroblasts, and endothelial cells of arteries undergoing accelerated atherosclerosis compared with normal coronary arteries.
Since RANTES is a ligand for the chemokine receptors CCR1 and CCR5, then these receptors, located on circulating mononuclear cells, may be useful therapeutic targets in transplantation biology. The importance of the CCR1 receptor was examined in heart transplantation models in mice carrying a targeted deletion in the CCR1 gene (Gao, W. et al., J. Clin. Invest (2000), Vol. 105, pp. 35-44). In this study, four separate models of allograft survival showed significant prolongation by CCR1 (xe2x88x92/xe2x88x92) recipients. In one model, levels of cyclosporin A that had marginal effects in CCR1 (+/+) mice resulted in permanent allograft acceptance in CCR1 (xe2x88x92/xe2x88x92) recipients.
Certain small molecules have recently been shown to be non-peptide CCR1 receptor antagonists by inhibiting the activity of RANTES and MIP-1xcex1 and are therefore useful as anti-inflammatory agents. See PCT Published patent application Ser. No. WO 98/56771, U.S. patent application, Ser. No. 09/094,397, filed Jun. 9, 1998, now U.S. Pat. No. 6,207,665, issued Mar. 27, 2001, Hesselgesser, J. et al, J. Biol. Chem. (1998), Vol. 273, pp. 15687-15692, Ng, H. P. et al, J. Med. Chem. (1999), Vol. 42, pp. 4680-4694, Liang, M. et al., Eur. J. Pharmacol (2000a), Vol. 389, pp. 41-49, and Liang, M. et al, J. Biol. Chem. (2000b), Vol. 275, pp. 19000-19008. The disclosures of these patent applications and journal articles are incorporated in full by reference herein.
Cyclosporins are a family of neutral lipophilic cyclic oligopeptides (11-mers) produced from the fungus Tolypocladium inflatum Gams, as well as other fungi imperfecti. The major component is cyclosporin A, a well-known commercially available immunosuppressive drug that selectively inhibits adaptive immune responses by blocking T cell activation (see Kahan, B. D., New Engl. J. Med. (1989), Vol. 321, pp. 1725-1738, and Valantine, H., Transplant Proc. (2000), Vol. 32, pp. 27S-44S). Although cyclosporin A has been a critical factor in the success of organ transplantation, there remains major long-term safety problems directly associated with cyclosporin A-based immunosuppression, including nephrotoxicity, hypertension, diabetes mellitis and post-transplant lymphoproliferative disease. It would therefore be desirable to be able to administer a sub-nephrotoxic dose of cyclosporin A, thereby reducing its unwanted side effects, while maintaining the immunosuppressive activity necessary to avoid chronic rejection, which, in the case of heart transplantation, is known as chronic allograft vasculopathy, principally manifested as accelerated arteriosclerosis.
Related Disclosures
In a recent renal transplant study, the peptide chemokine receptor antagonist Met-RANTES, when given with low doses of cyclosporin A, significantly reduced renal injury, including interstitial inflammation, mainly by reducing the number of infiltrating monocytes (Grxc3x6ne, H. J. et al., FASEB J. (1999), Vol. 13, pp. 1371-1383). This study supports the theory that RANTES, through activation of specific chemokine receptors on mononuclear cells, plays an important role in allograft rejection.
Published European Patent Application 1 000 626 (Applied Research Systems) discloses the use of a peptide chemokine receptor antagonist, Met-RANTES, together with a cyclosporin for treating or preventing rejection of transplanted organs, tissues or cells.
This invention is directed to pharmaceutical compositions useful in treating heart transplant rejection in mammals, which compositions comprise one or more pharmaceutically acceptable excipients, a therapeutically effective amount of a non-peptide CCR1 receptor antagonist and a sub-nephrotoxic amount of cyclosporin A. In particular, this invention is directed to pharmaceutical compositions useful in treating transplant rejection in mammals, which compositions comprise one or more pharmaceutically acceptable excipients, a sub-nephrotoxic amount of cyclosporin A and a therapeutically effective amount of a non-peptide CCR1 receptor antagonist selected from the compounds disclosed in U.S. Pat. No. 6,207,665.
This invention is also directed to methods of administering to a mammal in need thereof a pharmaceutical composition useful in treating heart transplant rejection in mammals, which composition comprises one or more pharmaceutically acceptable excipients, a therapeutically effective amount of a non-peptide CCR1 receptor antagonist and a sub-nephrotoxic amount of cyclosporin A. In particular, this invention is directed to methods of administering to a mammal in need thereof a pharmaceutical composition useful in treating heart transplant rejection in mammals, which composition comprises one or more pharmaceutically acceptable excipients, a sub-nephrotoxic amount of cyclosporin A, and a therapeutically effective amount of a non-peptide CCR1 receptor antagonist selected from the disclosed in U.S. Pat. No. 6,207,665.
This invention is also directed to methods of treating heart transplant rejection in a mammal which method comprises administering to a mammal in need thereof a pharmaceutical composition comprising one or more pharmaceutically acceptable excipients, a therapeutically effective amount of a non-peptide CCR1 receptor antagonist and a sub-nephrotoxic amount of cyclosporin A. In particular, this invention is directed to methods treating heart transplant rejection in a mammal which method comprises administering to a mammal in need thereof a pharmaceutical composition comprising one or more pharmaceutically acceptable excipients, a sub-nephrotoxic amount of cyclosporin A, and a therapeutically effective amount of a non-peptide CCR1 receptor antagonist selected from the compounds disclosed in U.S. Pat. No. 6,207,665.